Improvement in valve devices for fluid-brakes



UNITED STATES PATENT OFFICE.

GEORGE WESTINGHOUSE, JR, OF PITTSBURG, PENNSYLVANIA lMPROVEMENT IN VALVEDEVICES FOR FLUID-BRAKES.

Specification forming part of Letters Patent No. 141,685, dated August12, 1873 application filed May 24, 1e73.

To all whom it may concern:

Be it known that I, GEORGE \VESTING- HOUSE, Jr., of Pittsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Valve Device for Fluid Brakes; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof, reference being had to the accompanying drawing, whichrepresents in section my improved valve device,

vby allowing the compressed air thus stored up in each reservoir to passinto the brakecylinder. In such combination a triple valve has beendescribed of such construction and with such connections that, by acontinuous pressure of air in the brake-pipe, communication was keptopen thence to each reservoir and closed to the brake-cylinder, but keptopen from the latter to the external atmosphere 5 and, also, by loweringthe pressure of air in the brake-pipe, communication was opened fromeach reservoir to the brake-cylinder of the car, and all othercommunication closed.

My present invention relates to an improved construction of triplevalve, by means of which this operation is more advantageously effected,and has more particular reference to the construction of devices bywhich a flowof compressed air from each auxiliary reservoir to itsbrake-cylinder can be regulated at pleasure, and thereby the brakes beapplied with any desired degree of force less than the maximum.

To enable others skilled in the art to make and use my improvement, Iwill proceed to describe the same.

The valve-case G is of the form substantially as shown, so as to give avalve-chamber, G into which at or near one end a port, G, opens,

ing passage, B, and the air-port H communicates with the valve-chamberH. The valvestem g has a limited range of motion in the chamber G At ornear its lower end it carries a valve, a, which seats on the annular V-shaped seat a by suitable packing on its lower face. A spring, g,bearing against the cap of the valve-case G, and against the upper faceof the valve-seat 11, holds the lower valve to to its seat, when notraised therefrom by airpressure. The flexible diaphragm a divides thevalvechamber G into two parts. The outer edge of this diaphragm or ringa is compressed between an annular metallic ring, a, and a shoulder onthe valveease; and the inner edge of said ring around the stem 9 iscompressed between the different parts of the compound nut c c, whichnut is free to move vertically on the stem 9, and the upper face 0 ofwhich is provided with a suitable packing, so as to make a tight jointwhen brought against the annular ring of the valve-seat b.

(lommencin g at a point a short distance below the upper valve-seat I),the stem 9 is turned smaller or reduced in size, as at e, and is alsoslotted, as indicated at 0 This reduction in the size of the stem 9gives an annular airport, 0, by which communication is secured from theupper to the lower part of the valvechamber G The compound nut c c,which constitutes mechanically a piston, has a downward extension aroundthe stem g, as shown at d, by means of which, in moving up and down onthe stem y, it covers and uncovers the port 0, and thereby closes andopens communication between the upper and lower parts of thevalve-chamber G The lower end of the annular port 6 communicates withthe lower part of the valve-chamber G by means of ports 6 which may bemade in any desired number. Across the slot 6 in the stem 9 a cross-bar,s, is arranged, with its ends fixed in position in the adjacent walls ofthe nut c. From this slotted part c a pin, 8, extends down through andlengthwise of the stem ginto the chamber H. The lower end of the chamberH is fitted with a spring, h, which bears against the conical valve hhaving a suite ble packing on its conical face. Such valve is arrangedin its chamber so as to open and close the escape-ports 7L2. This valveis attached to a ste1n,h which, by means of wings of the usual form,causes the valve h to move vertically in its chamber in opening andclosing the ports 7L2. The pin 8 is of such length and position thatwith the downward movement of the piston c c" the crossbar 8 will becaused to bear against its upper end and force its lower end against thestem h of the valve 71. and thereby throw it from its seat and uncoverthe ports h. The conical plug 0 is attached to the lower end of the stemg in such position as to enter the port 0, which connects the chambers Gand H; but this plug 0 is of such shape as to graduate the size of theopening of the port 0, accordingly as it is raised more or less by theupward movement of the stem g. The valve-case described is, by the portG connected with the brakepipes, by the port G with the auxiliary reser*voir, and by the port H with the brake-cylinder. If air or other gas orfluid under pressure be admitted by the port G it will cause the pistonc 0, with its diaphragm a, to be depressed or to slide down on the stem9 until it occupies about the position shown. The crossbar .9 will thenhave opened the valve M, and the valve to will be closed by means of thespring 9, or by fluid-pressure; also, the annular port 0 will open. Insuch case the air or other fluid will pass, as indicated by the an rows,from the upper part of the chamber G along the ports 0 6 into the lowerpart of the chamber G and out at the port G to the auxiliary reservoir,whereby the auxiliary reservoir will be charged with compressed air ofsuch density as it may be desired to store up for the purpose ofoperating the brakes. At the same time, by the means already described,the valve 7L1 is unseated, and thus a direct communication is openedfrom the brake-cylinder, through the port H, chamber H, and ports h,with the external atmosphere. The brakes are then off. As soon as thepressure on the upper and lower sides of the diaphragm n and compoundnut c c is equal, or nearly so, the spring h in the lower part of thecase, acting against the valve k through the stem k pin 8, crossbar s,will cause the piston c c to slide upward on the stem g, and thereby cut011' communication through the annular passage 0, and will seat thevalve h so as to close the escape-ports h. Then, if the pressure abovethe diaphragm n be reduced by allowing a portion of the air to escapefrom the brake-pipes, the pressure of the air or other gas, acting backthrough the port (l on the under side of the diaphragm a, will raise thepiston c 0 against the valve-seat b,

compress the spring 9, and, by raising the stem g vertically upward,will lift the valve to from its seat a, and thereby open communicationfrom the chamber G through the port ,0, chamber H, with the port H. The

compressed air or other gas or fluid will then be free to pass from theauxiliary reservoir, through the ports GR, 0, and H, to thebrakecylinder, so as to charge the same and apply the brakes in theusual way. The area of the opening through the port 0 is regulatedby thedistance which the plug 0 is caused to move vertically upward. Hence, ifthe pressure he reduced but slightly at G, the plug 0 will be raised buta short distance, and a small amount of compressed air or other fluidwill be allowed to pass through and out at the port H. WVhen theequilibrium is thereby restored in the chamber G the valve a will resumeits seat and close the communication. If the pressure in the upper partof the chamber G be materially increased, the lower valve h will beunseated, as already described, and an open communication be made fromthe brakecylinder, through the port H and 71/2, to the externalatmosphere. By the use of the taper plug 0, in the manner described, andby regulating, as can easily be done by the use of suitable cooks, theamount of pressure in the upper and lower parts of the chamber G it iseasy to regulate the amount or density of the air which is permitted toflow through the port 0 into the brake-cylinder, and consequently easyto regulate and adjust, at all times, the force with which the brakesare applied, and such force may be varied from the maximum power of thebrakes down to the fractional part of a pound, in excess of ordinaryatmospheric pressure.

The construction of the piston may be varied somewhat, provided itsoperation and function remain substantially unchanged.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The piston c 0, having separate and independently-operatingconnections to, and in combination with, a charging-valve, a, anddischarging-valve h, whereby the dischargingvalve shall be closed at orbefore the opening of the charging-valve, substantially as set forth.

2. The )in s cross-bar s and stem in combination with the piston c c,valves to and 701, and plug 0, arranged substantially as set forth.

In testimony whereof I, the said GEORGE WEsrINGnoUsE, Jr., have hereuntoset my hand.

GEORGE WESTINGHOUSE, JR.

Witnesses:

'l. B. KERR, G. H. Onms'rv.

